I’ll try to keep this short....
1968 F100 390/auto

the truck has always been slow to start when hot. I figured it was from headers over heating the starter.
i eventually put a new starter on it. Had no problems for awhile. The other night I drove it, shut it off for 15 minutes and it wouldn’t start back up. I walked to parts store put in a new battery since the old one was 6 years old. It started right up. I thought that was the problem.
Went for a 20 minute drive the other day and it wouldn’t restart, got a jump and away I went.
huh, I guess its not charging.
I put on a new solenoid, battery, and an alternator that I had on shelf that looks brand new and also a voltage regulator that I pulled off another truck.
Still not charging.

also

When I plug in the new regulator the alternator starts making a high pitched wine and the wires get hot immediately. I can also smell an electrical smell.
I unplug the regulator and the noise goes away.

I think I’ll get a new regulator and alternator, since I just got the solenoid and battery from the parts store.


Anybody ever deal with this?
why does my alternator make that sound
and start to melt down when i plug in the regulator?
the reg. is the same as the one that’s in there.

What am I overlooking?

Thanks!
its a great day to be outside getting something done.

Ron

 

Check the voltage regulator wiring and plug to be in good condition. But it sounds like that used regulator has an internal short to ground. Replace it with a new one of a good brand.

 

Yes, what he said.

 

And keep your old starter relay/solenoid too! As a spare of whatever, since many of the new ones don't last that long. If they work at all.

And for future reference the starter relay has ZERO to do with a no-charge situation. That's because the alternator charges the battery with a connection directly to the battery cable. Yes, it might be there at the starter relay, but since both cables are on the same stud, they are in direct contact with each other so no matter how bad a starter relay gets, or how corroded/rusty the stud, if the two wires (charge and battery) have good contact with each other, nothing else is going to keep that connection from working.

Good luck with your issue. Lots of tests that can be done prior to changing parts. The charging system is relatively simple as things go.
By the way, which wires were getting hot? The big Black wire from the alternator? The little ones at the regulator? Some others in the area?

Paul

 

They got more than hot!

i replaced the alternator and I have several regulators, I tried swapping them out and in The process I melted the small wire that runs to the regulator.

I’m guessing the problems started either by a mouse chewing the wires, or more than likely it stopped charging due to things getting corroded from sitting, and in the process of swapping things around I hooked the wires up backwards.

iwas pretty confident that I hooked them up correctly
because as I’m sure you know, the wires retain their course/shape from being in same position for years.

I’ll have to replace that wire and start over.

I wasn’t paying attention to what I was doing.

Thanks for your help.

 

Darn mice! I hates them meeces to pieces!

Glad you figured it out and that it was only one small wire. Hope you get it back up and charging soon.

Paul

 

Here’s what got, Orange FLD goes to F on Reg, the white GRD goes to S on Reg. and there’s a ground wire running between the Alt case and mounting bolt of Reg.
does that seem correct?

 

I hooked the wires up using the “muscle memory” of the wires.

When I had the white wire connected to the STA post of the Alt, I fried the Reg. although it was charging at about 14.25 volts going to the battery.

The way it’s hooked up now (in the pic) makes no sense. White wire goes from GRD on the Alt to the S on the Reg???
I haven’t started it the way it’s hooked up now, because I don’t want to fry anything else.

Thanks

 

Good! It's not correct. A ground is just a ground and has no business on one of the regulator contact points. ONLY to one of the mounting bolts.

However, your White w/black wire is in fact the stator wire, so it must go to the stator terminal for it to be of any use.
I don't remember if you said, but does your truck have a battery charge indicator light, or an ammeter? Judging by the fact that a '68 even has a stator wire, I'm guessing you have a light and not an ammeter?
Let us know before you proceed. Even though I think we know the answer.

Based on the configuration of your 4-wire regulator plug, you have a lamp. And the wires only go to one place each and that's how they work. Any problems you had before were due to defects or faults, and not the way the regulator is wired.

F is the Orange field wire. As you have it.
S is the White w/black stator wire. Fix that.
A is the Yellow armature wire. Gets direct battery voltage at all times. Check that if you have not.
I is the Green w/red Indicator/Ignition wire. Comes from the ignition switch and has 12v in RUN only. Not in ACC. Check that too if you have not.

The heavy whining you got last time was probably the alternator going into overload. Bad regulator maybe? Any wires getting hot either had too much resistance, too much current from the overworked alternator, or were somehow seeing power they were not supposed to.
In all this did you check your main grounds? You should have three to worry about:
1. Your main battery cable ground to the engine block. Should be newer, of good size (6ga is underkill and should be upgraded, 2ga is just the right overkill), have clean contact and be nice and tight.
2. Body ground from negative battery to the body nearby, on the fender somewhere.
3. Engine-to-body ground from back of engine to firewall.

Making sure these are all good should keep your wires from getting hot unless there is still a fault in the alternator wiring.
Check the Yellow wire to make sure it has exactly the same voltage as the battery. Jiggle the wire while testing to make sure it's got a good contact.
Check the Green w/red wire with the key ON and it should have 12v or near battery voltage. With the key off it should have nothing.

Paul

 

Also, the original issue of slow starting when cranking can be weak battery cables. They should be renewed more often than most people realize. Even new ones can go bad internally.

What do you have on there now, and can we see some pics? The pics of the alternator and regulator really helped!
Slow cranking when hot can be any of, or any combination of three common things.

1. Older starter, having trouble with the heat.
2. Too much ignition advance making it hard to push past the dynamic pressure in the cylinders.
3. Undersized, or under-performing battery cables.

Of course you could add a fourth item in the battery, but that's kind of a given anyway. Batteries get old, they get weak, and frankly they can be just enough undersized to begin with to create the conditions under which the problem arises.
Which is why with batteries and battery cables alike, oversize is better than undersize because it gives you more headroom when things start to deteriorate. In this category, "overkill is just enough" as we like to say.

Paul

 

I will test run this set up without plugging the harness into the Reg.

Voltage test with key off and the harness reads—

F-0.0
S-.02
A-12.5
I-0.0

With key on-

F-0.0
S-.02
A-12.2
I-12


I have a non working ammeter.
It hasn’t worked since I got the truck.

When I had the white wire hooked to the stator post, I fried my Reg. I’m going to check out the other wires before I fire it up again.

It doesn’t make any sense. I have been driving the truck in the configuration it’s in for several years. It sat all this winter for no reason other than I have other vehicles to drive, and I figured the sitting around had caused some corrosion.

I appreciate your help.

Ron

 

Ok, so I have literally NEVER seen a Ford with your wiring configuration. Either in person, or in any diagram. So hopefully someone else has.
Do you know if it's the original wire harness under the hood? Could someone have changed it?
Perhaps they changed the instrument cluster instead? Or is it an aftermarket ammeter?

How do you know you fried the regulator when you connected the stator wire? Since the system was not charging to begin with, your regulator may already have been dead.
Which wires got hot? Might still be due to the bad regulator.
Your system does not work, so you need to run down every wire now. As you have already shown concern about, you can't just wire it up wrong in a different way hoping it will work. If it worked the old way, you have to hook it back up that way and find out why it's not working. It did once, so unless you changed the wires around, it should once again in this configuration.

My concern, and the reason for my questions about the ammeter, is that NO FORD that I've ever come across had an ammeter and all four wires at the regulator connected. There are usually only three wires with an ammeter equipped truck.
And I've only see all four wires connected when there was not an ammeter from the factory. And since both types are wired differently, never the twain shall meet.

Here's how yours is supposed to be wired (with 4-wires and NO ammeter):

F - still goes to the FLD terminal on the alternator like you have it.
S - needs to go to the STA terminal on the alternator. If it still melts things, then you have another issue besides the factory wiring it wrong.
A - Still gets a constant 12v from the battery. This is the sensing wire and tells the regulator to tell how the alternator how much juice to produce.
I - Needs 12v with the key ON.

Another question. Do you have a BAT indicator light at all on the dash? If so, does it come on when you turn the key to ON?
Either way, the Green w/red I wire needs 12v with the key to turn the system on.

Something obviously changed while the truck sat. But unless someone came over and switched things around, it must involve wiring and/or component deterioration. No need then for you to change the termination points of any wires. Leave it the way you had it originally and find out where the new problem is with the wiring.

Still quite a few possibilities unfortunately. Wish I could tell you it was going to be simpler, but until we know that ammeter and that charging system are original, we can only go by the known diagrams.
And check each wire for it's continued proper function.

Paul

 

The truck is a mish-mash of parts I’m sure.


I know the Reg fried by the smoke coming out of it.


I gotta sit back and scratch my head a little bit to figure this one out.
Ill include dash pic to show my gauges.

 

Great, thanks for the pic. I'll go look at the diagrams I can find for a '68 and see how the ammeter and regulator are wired, in case it's different from the ones I am more familiar with.
It's entirely possible that someone swapped either a gauge cluster OR an alternator harness. It's easy, and I've seen people do even more, like putting a different cab on a frame, so we could be dealing with anything.
Most of our later ammeters did not work either (especially true of the '73 through '79 models. That just makes it harder to figure out. I know you could get a Marti Report for your '68 so that would be one way of knowing if it was ordered with gauges or not. Hmm, maybe the basic one for a few bucks will give that info? Or does someone have to buy the whole deluxe model to get that info? I got the Deluxe for my Bronco, but not sure what the cutoff is.

Either way though, we should be able to make a simple charging system work. Frankly, even though I'm not one of those "Swap in a 3G or go home" kind of people. I happen to like both our old 1G's and the newer 3G's, so have no preference. But this is certainly an instance where I can see the advantage of going all self-contained like an internally regulated alternator.
So keep that in the back of your mind as a final option.

In the meantime though, let's see what we can do with the parts on hand.
Be back after dinner...

Paul

 

Are you sure it is a voltage regulator meant for a Ford? Decades ago I ran across a vehicle who's regulator plug looked just like a Ford plug. My full field testing plug for a Ford even fit in to it. Come to find out even though it looked like a Ford, it's wires were in a different order. Might have been a Chrysler product. Don't remember.
Even if it is, get that "short circuit protected" regulator off there. That circuit is probably wired wrong internally and where the smoke came from. As a retired Ford Parts man of 41 years, I can guarantee that is not a genuine Ford product and of equal quality.. I have a low opinion of it. And it's internal condition. The best way to guarantee your problem is not the regulator, buy a Genuine Ford (motorcraft) regulator. Part number FOPZ10316A. They are NOT made in China.